Final answer:
Flat feet in an 18-month-old toddler can be considered normal as the arches of their feet are still developing. However, it is important to seek medical advice if flat feet persist or cause pain or difficulty walking.
Step-by-step explanation:
Flat feet in an 18-month-old toddler can be considered as normal. At this age, the arches of the feet are still developing and may not be fully formed yet. Most toddlers develop normal arches in their feet by the age of 6 years old.
It is important to note that if flat feet persist or are accompanied by pain or difficulty walking, it is recommended to consult a healthcare professional for further evaluation.